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# ================================================================================ | |
# Project: Kivy.Statechart - A Statechart Framework for Kivy | |
# Copyright: ©2010, 2011 Michael Cohen, and contributors. | |
# Python Port: Jeff Pittman, ported from SproutCore, SC.Statechart | |
# ================================================================================ | |
from kivy.statechart.system.state import State | |
from kivy.statechart.mixins.statechart_delegate import StatechartDelegate | |
from kivy.properties import AliasProperty | |
from kivy.logger import Logger | |
from collections import deque | |
""" | |
@class | |
The startchart manager mixin allows an object to be a statechart. By becoming a statechart, the | |
object can then be manage a set of its own states. | |
This implementation of the statechart manager closely follows the concepts stated in D. Harel's | |
original paper "Statecharts: A Visual Formalism For Complex Systems" | |
(www.wisdom.weizmann.ac.il/~harel/papers/Statecharts.pdf). | |
The statechart allows for complex state heircharies by nesting states within states, and | |
allows for state orthogonality based on the use of concurrent states. | |
At minimum, a statechart must have one state: The root state. All other states in the statechart | |
are a decendents (substates) of the root state. | |
The following example shows how states are nested within a statechart: | |
MyApp.Statechart = Object.extend(StatechartManager, { | |
rootState: State.design({ | |
initialSubstate: 'stateA', | |
stateA: State.design({ | |
# ... can continue to nest further states | |
}), | |
stateB: State.design({ | |
# ... can continue to nest further states | |
}) | |
}) | |
}); | |
Note how in the example above, the root state as an explicit initial substate to enter into. If no | |
initial substate is provided, then the statechart will default to the the state's first substate. | |
You can also defined states without explicitly defining the root state. To do so, simply create properties | |
on your object that represents states. Upon initialization, a root state will be constructed automatically | |
by the mixin and make the states on the object substates of the root state. As an example: | |
MyApp.Statechart = Object.extend(StatechartManager, { | |
initialState: 'stateA', | |
stateA: State.design({ | |
# ... can continue to nest further states | |
}), | |
stateB: State.design({ | |
# ... can continue to nest further states | |
}) | |
}); | |
If you liked to specify a class that should be used as the root state but using the above method to defined | |
states, you can set the rootStateExample property with a class that extends from State. If the | |
rootStateExample property is not explicitly assigned the then default class used will be State. | |
To provide your statechart with orthogonality, you use concurrent states. If you use concurrent states, | |
then your statechart will have multiple current states. That is because each concurrent state represents an | |
independent state structure from other concurrent states. The following example shows how to provide your | |
statechart with concurrent states: | |
MyApp.Statechart = Object.extend(StatechartManager, { | |
rootState: State.design({ | |
substatesAreConcurrent: True, | |
stateA: State.design({ | |
# ... can continue to nest further states | |
}), | |
stateB: State.design({ | |
# ... can continue to nest further states | |
}) | |
}) | |
}); | |
Above, to indicate that a state's substates are concurrent, you just have to set the substatesAreConcurrent to | |
True. Once done, then stateA and stateB will be independent of each other and each will manage their | |
own current substates. The root state will then have more then one current substate. | |
To define concurrent states directly on the object without explicitly defining a root, you can do the | |
following: | |
MyApp.Statechart = Object.extend(StatechartManager, { | |
statesAreConcurrent: True, | |
stateA: State.design({ | |
# ... can continue to nest further states | |
}), | |
stateB: State.design({ | |
# ... can continue to nest further states | |
}) | |
}); | |
Remember that a startchart can have a mixture of nested and concurrent states in order for you to | |
create as complex of statecharts that suite your needs. Here is an example of a mixed state structure: | |
MyApp.Statechart = Object.extend(StatechartManager, { | |
rootState: State.design({ | |
initialSubstate: 'stateA', | |
stateA: State.design({ | |
substatesAreConcurrent: True, | |
stateM: State.design({ ... }) | |
stateN: State.design({ ... }) | |
stateO: State.design({ ... }) | |
}), | |
stateB: State.design({ | |
initialSubstate: 'stateX', | |
stateX: State.design({ ... }) | |
stateY: State.desgin({ ... }) | |
}) | |
}) | |
}); | |
Depending on your needs, a statechart can have lots of states, which can become hard to manage all within | |
one file. To modularize your states and make them easier to manage and maintain, you can plug-in states | |
into other states. Let's say we are using the statechart in the last example above, and all the code is | |
within one file. We could update the code and split the logic across two or more files like so: | |
# state_a.js | |
MyApp.StateA = State.extend({ | |
substatesAreConcurrent: True, | |
stateM: State.design({ ... }) | |
stateN: State.design({ ... }) | |
stateO: State.design({ ... }) | |
}); | |
# state_b.js | |
MyApp.StateB = State.extend({ | |
substatesAreConcurrent: True, | |
stateM: State.design({ ... }) | |
stateN: State.design({ ... }) | |
stateO: State.design({ ... }) | |
}); | |
# statechart.js | |
MyApp.Statechart = Object.extend(StatechartManager, { | |
rootState: State.design({ | |
initialSubstate: 'stateA', | |
stateA: State.plugin('MyApp.StateA'), | |
stateB: State.plugin('MyApp.StateB') | |
}) | |
}); | |
Using state plug-in functionality is optional. If you use the plug-in feature you can break up your statechart | |
into as many files as you see fit. | |
@author Michael Cohen | |
""" | |
class StatechartManager: | |
def __init__(self): | |
# Walk like a duck | |
self.isResponderContext = True | |
# Walk like a duck | |
self.isStatechart = True | |
""" | |
Indicates if this statechart has been initialized | |
@property {Boolean} | |
""" | |
self.statechartIsInitialized = False | |
""" | |
Optional name you can provide the statechart with. If set this will be included | |
in tracing and error output as well as detail output. Useful for | |
debugging/diagnostic purposes | |
""" | |
self.name = None | |
""" | |
The root state of this statechart. All statecharts must have a root state. | |
If this property is left unassigned then when the statechart is initialized | |
it will used the rootStateExample, initialState, and statesAreConcurrent | |
properties to construct a root state. | |
@see #rootStateExample | |
@see #initialState | |
@see #statesAreConcurrent | |
@property {State} | |
""" | |
self.rootState = None | |
""" | |
Represents the class used to construct a class that will be the root state for | |
this statechart. The class assigned must derive from State. | |
This property will only be used if the rootState property is not assigned. | |
@see #rootState | |
@property {State} | |
""" | |
self.rootStateExample = State | |
""" | |
Indicates what state should be the initial state of this statechart. The value | |
assigned must be the name of a property on this object that represents a state. | |
As well, the statesAreConcurrent must be set to False. | |
This property will only be used if the rootState property is not assigned. | |
@see #rootState | |
@property {String} | |
""" | |
self.initialState = None | |
""" | |
Indicates if properties on this object representing states are concurrent to each other. | |
If True then they are concurrent, otherwise they are not. If the True, then the | |
initialState property must not be assigned. | |
This property will only be used if the rootState property is not assigned. | |
@see #rootState | |
@property {Boolean} | |
""" | |
self.statesAreConcurrent = False | |
""" | |
Indicates whether to use a monitor to monitor that statechart's activities. If true then | |
the monitor will be active, otherwise the monitor will not be used. Useful for debugging | |
purposes. | |
@property {Boolean} | |
""" | |
self.monitorIsActive = False | |
""" | |
A statechart monitor that can be used to monitor this statechart. Useful for debugging purposes. | |
A monitor will only be used if monitorIsActive is true. | |
@property {StatechartMonitor} | |
""" | |
self.monitor = None | |
""" | |
Used to specify what property (key) on the statechart should be used as the trace property. By | |
default the property is 'trace'. | |
@property {String} | |
""" | |
self.statechartTraceKey = 'trace' | |
""" | |
Indicates whether to trace the statecharts activities. If true then the statechart will output | |
its activites to the browser's JS console. Useful for debugging purposes. | |
@see #statechartTraceKey | |
@property {Boolean} | |
""" | |
self.trace = False | |
""" | |
Used to specify what property (key) on the statechart should be used as the owner property. By | |
default the property is 'owner'. | |
@property {String} | |
""" | |
self.statechartOwnerKey = 'owner' | |
""" | |
Sets who the owner is of this statechart. If None then the owner is this object otherwise | |
the owner is the assigned object. | |
@see #statechartOwnerKey | |
@property {Object} | |
""" | |
self.owner = None | |
""" | |
Indicates if the statechart should be automatically initialized by this | |
object after it has been created. If True then initStatechart will be | |
called automatically, otherwise it will not. | |
@property {Boolean} | |
""" | |
self.autoInitStatechart = True | |
""" | |
If yes, any warning messages produced by the statechart or any of its states will | |
not be logged, otherwise all warning messages will be logged. | |
While designing and debugging your statechart, it's best to keep this value false. | |
In production you can then suppress the warning messages. | |
@property {Boolean} | |
""" | |
self.suppressStatechartWarnings = False | |
""" | |
A statechart delegate used by the statechart and the states that the statechart | |
manages. The value assigned must adhere to the {@link StatechartDelegate} mixin. | |
@property {Object} | |
@see StatechartDelegate | |
""" | |
self.delegate = None | |
""" | |
Computed property that returns an objects that adheres to the | |
{@link StatechartDelegate} mixin. If the {@link #delegate} is not | |
assigned then this object is the default value returned. | |
@see StatechartDelegate | |
@see #delegate | |
""" | |
self.statechartDelegate = AliasProperty(self._statechartDelegate, None, bind=('delegate')) | |
self.currentStates = AliasProperty(self._currentStates, None) | |
self.firstCurrentState = AliasProperty(self._firstCurrentState, None, bind=('currentStates')) | |
self.currentStateCount = AliasProperty(self._currentStateCount, None, bind=('currentStates')) | |
self.enteredStates = AliasProperty(self._enteredStates, None) | |
self.gotoStateActive = AliasProperty(self._gotoStateActive, None) | |
self.gotoStateSuspended = AliasProperty(self._gotoStateSuspended, None) | |
self.statechartLogPrefix = AliasProperty(self._statechartLogPrefix, None) | |
self.allowStatechartTracing = AliasProperty(self._allowStatechartTracing, None) | |
self.details = AliasProperty(self._details, None) | |
self.monitorIsActiveDidChange = AliasProperty(self._monitorIsActiveDidChange, None, bind=('monitorIsActive')) | |
def _statechartDelegate(self): | |
return self.delegateFor('isStatechartDelegate', self.delegate); | |
def initMixin(self): | |
if self.autoInitStatechart: | |
self.initStatechart() | |
def destroyMixin(self): | |
# self.removeObserver(self.statechartTraceKey, self, '_statechartTraceDidChange'); | |
del self.statechartTraceDidChange # [PORT] is this the equivalent of unbind? | |
self.rootState.destroy(); | |
self.rootState = None | |
""" | |
Initializes the statechart. By initializing the statechart, it will create all the states and register | |
them with the statechart. Once complete, the statechart can be used to go to states and send events to. | |
""" | |
def initStatechart(self): | |
if self.statechartIsInitialized: | |
return | |
self._gotoStateLocked = False | |
self._sendEventLocked = False | |
self._pendingStateTransitions = deque() | |
self._pendingSentEvents = deque() | |
self.sendAction = self.sendEvent | |
if self.monitorIsActive: | |
self.monitor = StatechartMonitor(this) | |
self.statechartTraceDidChange = AliasProperty(self._statechartTraceDidChange, None, bind=('statechartTraceKey')) | |
self._statechartTraceDidChange() # [PORT] this call needed for kivy? | |
trace = self.allowStatechartTracing | |
rootState = self.rootState | |
msg = '' | |
if trace: | |
self.statechartLogTrace("BEGIN initialize statechart") | |
# If no root state was explicitly defined then try to construct | |
# a root state class | |
if not rootState: | |
rootState = self._constructRootStateClass() | |
elif hasattr(rootState, '__call__') and rootState.statePlugin is not None: | |
rootState = rootState(self) | |
if not issubclass(rootState, KivyState) and rootState.isClass: | |
msg = "Unable to initialize statechart. Root state must be a state class" | |
self.statechartLogError(msg) | |
raise Exception(msg) | |
rootState = self.createRootState(rootState, { statechart: self, name: ROOT_STATE_NAME }) | |
self.rootState = rootState | |
rootState.initState() | |
if issubclass(rootState.initialSubstate, EmptyState): | |
msg = "Unable to initialize statechart. Root state must have an initial substate explicilty defined" | |
self.statechartLogError(msg) | |
raise msg | |
if not empty(self.initialState): | |
key = 'initialState' | |
self.key = rootState[self.key] | |
self.statechartIsInitialized = True | |
self.gotoState(rootState) | |
if trace: | |
self.statechartLogTrace("END initialize statechart") | |
""" | |
Will create a root state for the statechart | |
""" | |
def createRootState(self, state, attrs): | |
if attrs is None: | |
attrs = {} | |
state = state(attrs) | |
return state | |
""" | |
Returns an array of all the current states for this statechart | |
@returns {Array} the current states | |
""" | |
def _currentStates(self): | |
return self.rootState.currentSubstates | |
""" | |
Returns the first current state for this statechart. | |
@return {State} | |
""" | |
def _firstCurrentState(self): | |
return self.currentStates[0] if self.currentStates else None # [PORT] was objectAt 0 | |
""" | |
Returns the count of the current states for this statechart | |
@returns {Number} the count | |
""" | |
def _currentStateCount(self): | |
return self.currentStates.length | |
""" | |
Checks if a given state is a current state of this statechart. | |
@param state {State|String} the state to check | |
@returns {Boolean} true if the state is a current state, otherwise fals is returned | |
""" | |
def stateIsCurrentState(self): | |
return self.rootState.stateIsCurrentSubstate(state) | |
""" | |
Returns an array of all the states that are currently entered for | |
this statechart. | |
@returns {Array} the currently entered states | |
""" | |
def _enteredStates(self): | |
return self.rootState.enteredSubstates | |
""" | |
Checks if a given state is a currently entered state of this statechart. | |
@param state {State|String} the state to check | |
@returns {Boolean} true if the state is a currently entered state, otherwise false is returned | |
""" | |
def stateIsEntered(self, state): | |
return self.rootState.stateIsEnteredSubstate(state) | |
""" | |
Checks if the given value represents a state is this statechart | |
@param value {State|String} either a state object or the name of a state | |
@returns {Boolean} true if the state does belong ot the statechart, otherwise false is returned | |
""" | |
def doesContainState(self, value): | |
return self.getState(value) is not None | |
""" | |
Gets a state from the statechart that matches the given value | |
@param value {State|String} either a state object of the name of a state | |
@returns {State} if a match then the matching state is returned, otherwise None is returned | |
""" | |
def getState(self, state): | |
return self.rootState if self.rootState is state else self.rootState.getSubstate(state) | |
""" | |
When called, the statechart will proceed with making state transitions in the statechart starting from | |
a current state that meet the statechart conditions. When complete, some or all of the statechart's | |
current states will be changed, and all states that were part of the transition process will either | |
be exited or entered in a specific order. | |
The state that is given to go to will not necessarily be a current state when the state transition process | |
is complete. The final state or states are dependent on factors such an initial substates, concurrent | |
states, and history states. | |
Because the statechart can have one or more current states, it may be necessary to indicate what current state | |
to start from. If no current state to start from is provided, then the statechart will default to using | |
the first current state that it has; depending of the make up of the statechart (no concurrent state vs. | |
with concurrent states), the outcome may be unexpected. For a statechart with concurrent states, it is best | |
to provide a current state in which to start from. | |
When using history states, the statechart will first make transitions to the given state and then use that | |
state's history state and recursively follow each history state's history state until there are no | |
more history states to follow. If the given state does not have a history state, then the statechart | |
will continue following state transition procedures. | |
Method can be called in the following ways: | |
# With one argument. | |
gotoState(<state>) | |
# With two argument. | |
gotoState(<state>, <state | boolean | hash>) | |
# With three argument. | |
gotoState(<state>, <state>, <boolean | hash>) | |
gotoState(<state>, <boolean>, <hash>) | |
# With four argument. | |
gotoState(<state>, <state>, <boolean>, <hash>) | |
where <state> is either a State object or a string and <hash> is a regular JS hash object. | |
@param state {State|String} the state to go to (may not be the final state in the transition process) | |
@param fromCurrentState {State|String} Optional. The current state to start the transition process from. | |
@param useHistory {Boolean} Optional. Indicates whether to include using history states in the transition process | |
@param context {Hash} Optional. A context object that will be passed to all exited and entered states | |
""" | |
def gotoState(self, state, fromCurrentState, useHistory, context): | |
if not self.statechartIsInitialized: | |
self.statechartLogError("can not go to state {0}. statechart has not yet been initialized".format(state)) | |
return | |
if self.isDestroyed: | |
self.statechartLogError("can not go to state {0}. statechart is destroyed".format(this)) | |
return | |
args = self._processGotoStateArgs(arguments) | |
state = args.state | |
fromCurrentState = args.fromCurrentState | |
useHistory = args.useHistory | |
context = args.context | |
pivotState = None | |
exitStates = deque() | |
enterStates = deque() | |
trace = self.allowStatechartTracing | |
rootState = self.rootState | |
paramState = state | |
paramFromCurrentState = fromCurrentState | |
msg = '' | |
state = self.getState(state) | |
if state is None: | |
self.statechartLogError("Can not to goto state {0}. Not a recognized state in statechart".format(paramState)) | |
return | |
if self._gotoStateLocked: | |
# There is a state transition currently happening. Add this requested state | |
# transition to the queue of pending state transitions. The request will | |
# be invoked after the current state transition is finished. | |
self._pendingStateTransitions.append({ | |
state: state, | |
fromCurrentState: fromCurrentState, | |
useHistory: useHistory, | |
context: context | |
}) | |
return | |
# Lock the current state transition so that no other requested state transition | |
# interferes. | |
self._gotoStateLocked = True | |
if fromCurrentState is not None: | |
# Check to make sure the current state given is actually a current state of this statechart | |
fromCurrentState = self.getState(fromCurrentState) | |
if fromCurrentState is None or not fromCurrentState.isCurrentState: | |
msg = "Can not to goto state {0}. {1} is not a recognized current state in statechart" | |
self.statechartLogError(msg.format(paramState, paramFromCurrentState)) | |
self._gotoStateLocked = False | |
return | |
else: | |
# No explicit current state to start from; therefore, need to find a current state | |
# to transition from. | |
fromCurrentState = state.findFirstRelativeCurrentState() | |
if fromCurrentState is None: | |
fromCurrentState = self.firstCurrentState | |
if trace: | |
self.statechartLogTrace("BEGIN gotoState: {0}".format(state)) | |
msg = "starting from current state: {0}" | |
msg = msg.format(fromCurrentState if fromCurrentState else '---') | |
self.statechartLogTrace(msg) | |
msg = "current states before: {0}" | |
msg = msg.format(self.currentStates if len(self.currentStates) > 0 else '---') | |
self.statechartLogTrace(msg) | |
# If there is a current state to start the transition process from, then determine what | |
# states are to be exited | |
if fromCurrentState is not None: | |
exitStates = self._createStateChain(fromCurrentState) | |
# Now determine the initial states to be entered | |
enterStates = self._createStateChain(state) | |
# Get the pivot state to indicate when to go from exiting states to entering states | |
pivotState = self._findPivotState(exitStates, enterStates) | |
if pivotState is not None: | |
if trace: | |
self.statechartLogTrace("pivot state = {0}".format(pivotState)) | |
if pivotState.substatesAreConcurrent and pivotState is not state: | |
self.statechartLogError("Can not go to state {0} from {1}. Pivot state {2} has concurrent substates.".format(state, fromCurrentState, pivotState)) | |
self._gotoStateLocked = False | |
return | |
# Collect what actions to perform for the state transition process | |
gotoStateActions = [] | |
# Go ahead and find states that are to be exited | |
self._traverseStatesToExit(exitStates.rotate(), exitStates, pivotState, gotoStateActions) # [PORT] rotate was shift | |
# Now go find states that are to entered | |
if pivotState is not state: | |
self._traverseStatesToEnter(enterStates.pop(), enterStates, pivotState, useHistory, gotoStateActions) | |
else: | |
self._traverseStatesToExit(pivotState, deque(), None, gotoStateActions) | |
self._traverseStatesToEnter(pivotState, None, None, useHistory, gotoStateActions) | |
# Collected all the state transition actions to be performed. Now execute them. | |
self._gotoStateActions = gotoStateActions | |
self._executeGotoStateActions(state, gotoStateActions, None, context) | |
""" | |
Indicates if the statechart is in an active goto state process | |
""" | |
def _gotoStateActive(self): | |
return self._gotoStateLocked | |
""" | |
Indicates if the statechart is in an active goto state process | |
that has been suspended | |
""" | |
def _gotoStateSuspended(self): | |
return self._gotoStateLocked and self._gotoStateSuspendedPoint is not None # [PORT] this was !!self._gotoStateSuspendedPoint -- boolean force? | |
""" | |
Resumes an active goto state transition process that has been suspended. | |
""" | |
def resumeGotoState(self): | |
if not self.gotoStateSuspended: | |
self.statechartLogError("Can not resume goto state since it has not been suspended") | |
return | |
point = self._gotoStateSuspendedPoint | |
self._executeGotoStateActions(point.gotoState, point.actions, point.marker, point.context) | |
""" @private """ | |
def _executeGotoStateActions(self, gotoState, actions, marker, context): | |
action = None | |
len = actions.length | |
actionResult = None | |
marker = 0 if marker is None else marker | |
while marker < len: | |
self._currentGotoStateAction = action = actions[marker] | |
if action.action is EXIT_STATE: | |
actionResult = self._exitState(action.state, context) | |
elif action.action is ENTER_STATE: | |
actionResult = self._enterState(action.state, action.currentState, context) | |
# Check if the state wants to perform an asynchronous action during | |
# the state transition process. If so, then we need to first | |
# suspend the state transition process and then invoke the | |
# asynchronous action. Once called, it is then up to the state or something | |
# else to resume this statechart's state transition process by calling the | |
# statechart's resumeGotoState method. | |
# | |
if issubclass(actionResult, Async): | |
self._gotoStateSuspendedPoint = { | |
gotoState: gotoState, | |
actions: actions, | |
marker: marker + 1, | |
context: context | |
} | |
actionResult.tryToPerform(action.state) | |
return | |
marker += 1 | |
self.beginPropertyChanges() | |
#self.notifyPropertyChange('currentStates') # [PORT] notify needed here in kivy? | |
#self.notifyPropertyChange('enteredStates') # [PORT] notify needed here in kivy? | |
self.endPropertyChanges() | |
if self.allowStatechartTracing: | |
self.statechartLogTrace("current states after: {0}".format(self.currentStates)) | |
self.statechartLogTrace("END gotoState: {0}".format(gotoState)) | |
self._cleanupStateTransition() | |
""" @private """ | |
def _cleanupStateTransition(self): | |
self._currentGotoStateAction = None | |
self._gotoStateSuspendedPoint = None | |
self._gotoStateActions = None | |
self._gotoStateLocked = False | |
self._flushPendingStateTransition() | |
""" @private """ | |
def _exitState(self, state, context): | |
parentState = None | |
if (state.currentSubstates.find(state) >= 0): | |
parentState = state.parentState | |
while parentState is not None: | |
parentState.currentSubstates.removeObject(state) | |
parentState = parentState.parentState | |
parentState = state; | |
while parentState is not None: | |
parentState.enteredSubstates.removeObject(state) | |
parentState = parentState.parentState | |
if self.allowStatechartTracing: | |
self.statechartLogTrace("<-- exiting state: {0}".format(state)) | |
state.currentSubstates = [] | |
state.stateWillBecomeExited(context) | |
result = self.exitState(state, context) | |
state.stateDidBecomeExited(context) | |
if self.monitorIsActive: | |
self.monitor.pushExitedState(state) | |
state._traverseStatesToExit_skipState = False | |
return result | |
""" | |
What will actually invoke a state's exitState method. | |
Called during the state transition process whenever the gotoState method is | |
invoked. | |
@param state {State} the state whose enterState method is to be invoked | |
@param context {Hash} a context hash object to provide the enterState method | |
""" | |
def exitState(self, state, context): | |
return state.exitState(context) | |
""" @private """ | |
def _enterState(self, state, current, context): | |
parentState = state.parentState | |
if parentState and not state.isConcurrentState: | |
parentState.historyState = state | |
if current: | |
parentState = state | |
while parentState is not None: | |
parentState.currentSubstates.append(state) | |
parentState = parentState.parentState | |
parentState = state; | |
while parentState is not None: | |
parentState.enteredSubstates.append(state) | |
parentState = parentState.parentState | |
if self.allowStatechartTracing: | |
self.statechartLogTrace("--> entering state: {0}".format(state)) | |
state.stateWillBecomeEntered(context) | |
result = self.enterState(state, context) | |
state.stateDidBecomeEntered(context) | |
if self.monitorIsActive: | |
self.monitor.pushEnteredState(state) | |
return result | |
""" | |
What will actually invoke a state's enterState method. | |
Called during the state transition process whenever the gotoState method is | |
invoked. | |
If the context provided is a state route context object | |
({@link StateRouteContext}), then if the given state has a enterStateByRoute | |
method, that method will be invoked, otherwise the state's enterState method | |
will be invoked by default. The state route context object will be supplied to | |
both enter methods in either case. | |
@param state {State} the state whose enterState method is to be invoked | |
@param context {Hash} a context hash object to provide the enterState method | |
""" | |
def enterState(self, state, context): | |
if state.enterStateByRoute and issubclass(context, StateRouteHandlerContext): | |
return state.enterStateByRoute(context) | |
else: | |
return state.enterState(context) | |
""" | |
When called, the statechart will proceed to make transitions to the given state then follow that | |
state's history state. | |
You can either go to a given state's history recursively or non-recursively. To go to a state's history | |
recursively means to following each history state's history state until no more history states can be | |
followed. Non-recursively means to just to the given state's history state but do not recusively follow | |
history states. If the given state does not have a history state, then the statechart will just follow | |
normal procedures when making state transitions. | |
Because a statechart can have one or more current states, depending on if the statechart has any concurrent | |
states, it is optional to provided current state in which to start the state transition process from. If no | |
current state is provided, then the statechart will default to the first current state that it has; which, | |
depending on the make up of that statechart, can lead to unexpected outcomes. For a statechart with concurrent | |
states, it is best to explicitly supply a current state. | |
Method can be called in the following ways: | |
# With one arguments. | |
gotoHistorytate(<state>) | |
# With two arguments. | |
gotoHistorytate(<state>, <state | boolean | hash>) | |
# With three arguments. | |
gotoHistorytate(<state>, <state>, <boolean | hash>) | |
gotoHistorytate(<state>, <boolean>, <hash>) | |
# With four argumetns | |
gotoHistorytate(<state>, <state>, <boolean>, <hash>) | |
where <state> is either a State object or a string and <hash> is a regular JS hash object. | |
@param state {State|String} the state to go to and follow it's history state | |
@param fromCurrentState {State|String} Optional. the current state to start the state transition process from | |
@param recursive {Boolean} Optional. whether to follow history states recursively. | |
""" | |
def gotoHistoryState(self, state, fromCurrentState, recursive, context): | |
if not self.statechartIsInitialized: | |
self.statechartLogError("can not go to state {0}'s history state. Statechart has not yet been initialized".format(state)) | |
return | |
args = self._processGotoStateArgs(arguments) | |
state = args.state | |
fromCurrentState = args.fromCurrentState | |
recursive = args.useHistory | |
context = args.context | |
state = self.getState(state) | |
if state is None: | |
self.statechartLogError("Can not to goto state {0}'s history state. Not a recognized state in statechart".format(state)) | |
return | |
historyState = state.historyState | |
if not recursive: | |
if historyState is not None: | |
self.gotoState(historyState, fromCurrentState, context) | |
else: | |
self.gotoState(state, fromCurrentState, context) | |
else: | |
self.gotoState(state, fromCurrentState, True, context) | |
""" | |
Sends a given event to all the statechart's current states. | |
If a current state does can not respond to the sent event, then the current state's parent state | |
will be tried. This process is recursively done until no more parent state can be tried. | |
Note that a state will only be checked once if it can respond to an event. Therefore, if | |
there is a state S that handles event foo and S has concurrent substates, then foo will | |
only be invoked once; not as many times as there are substates. | |
@param event {String} name of the event | |
@param arg1 {Object} optional argument | |
@param arg2 {Object} optional argument | |
@returns {Responder} the responder that handled it or None | |
@see #stateWillTryToHandleEvent | |
@see #stateDidTryToHandleEvent | |
""" | |
def sendEvent(self, event, arg1, arg2): | |
if self.isDestroyed: | |
self.statechartLogError("can send event {0}. statechart is destroyed".format(event)) | |
return | |
statechartHandledEvent = False | |
eventHandled = False | |
currentStates = self.currentStates[:] | |
checkedStates = {} | |
state = None | |
trace = self.allowStatechartTracing | |
if self._sendEventLocked or self._goStateLocked: | |
# Want to prevent any actions from being processed by the states until | |
# they have had a chance to handle the most immediate action or completed | |
# a state transition | |
self._pendingSentEvents.append({ | |
event: event, | |
arg1: arg1, | |
arg2: arg2 | |
}) | |
return | |
self._sendEventLocked = True | |
if trace: | |
self.statechartLogTrace("BEGIN sendEvent: '{0}'".format(event)) | |
for i in range(len(currentStates)): | |
eventHandled = False | |
state = currentStates[i] | |
if not state.isCurrentState: | |
continue | |
while not eventHandled and state is not None: | |
if not checkedStates[state.fullPath]: | |
eventHandled = state.tryToHandleEvent(event, arg1, arg2) | |
checkedStates[state.fullPath] = True | |
if not eventHandled: | |
state = state.parentState | |
else: | |
statechartHandledEvent = True | |
# Now that all the states have had a chance to process the | |
# first event, we can go ahead and flush any pending sent events. | |
self._sendEventLocked = False | |
if trace: | |
if not statechartHandledEvent: | |
self.statechartLogTrace("No state was able handle event {0}".format(event)) | |
self.statechartLogTrace("END sendEvent: '{0}'".format(event)) | |
result = self._flushPendingSentEvents() | |
return self if statechartHandledEvent else (self if result else None) | |
""" | |
Used to notify the statechart that a state will try to handle event that has been passed | |
to it. | |
@param {State} state the state that will try to handle the event | |
@param {String} event the event the state will try to handle | |
@param {String} handler the name of the method on the state that will try to handle the event | |
""" | |
def stateWillTryToHandleEvent(self, state, event, handler): | |
self._stateHandleEventInfo = { | |
state: state, | |
event: event, | |
handler: handler | |
} | |
""" | |
Used to notify the statechart that a state did try to handle event that has been passed | |
to it. | |
@param {State} state the state that did try to handle the event | |
@param {String} event the event the state did try to handle | |
@param {String} handler the name of the method on the state that did try to handle the event | |
@param {Boolean} handled indicates if the handler was able to handle the event | |
""" | |
def stateDidTryToHandleEvent(self, state, event, handler, handled): | |
self._stateHandleEventInfo = None | |
""" @private | |
Creates a chain of states from the given state to the greatest ancestor state (the root state). Used | |
when perform state transitions. | |
""" | |
def _createStateChain(self, state): | |
chain = deque() | |
while state is not None: | |
chain.append(state) | |
state = state.parentState | |
return chain | |
""" @private | |
Finds a pivot state from two given state chains. The pivot state is the state indicating when states | |
go from being exited to states being entered during the state transition process. The value | |
returned is the fist matching state between the two given state chains. | |
""" | |
def _findPivotState(self, stateChain1, stateChain2): | |
if len(stateChain1) is 0 or len(stateChain2) is 0: | |
return None | |
for state in stateChain1: | |
if stateChain2.find(state) >= 0: | |
return state | |
""" @private | |
Recursively follow states that are to be exited during a state transition process. The exit | |
process is to start from the given state and work its way up to when either all exit | |
states have been reached based on a given exit path or when a stop state has been reached. | |
@param state {State} the state to be exited | |
@param exitStatePath {collections.deque} a deque representing a path of states that are to be exited | |
@param stopState {State} an explicit state in which to stop the exiting process | |
""" | |
def _traverseStatesToExit(self, state, exitStatePath, stopState, gotoStateActions): | |
if state is None or state is stopState: | |
return | |
trace = self.allowStatechartTracing | |
# This state has concurrent substates. Therefore we have to make sure we | |
# exit them up to this state before we can go any further up the exit chain. | |
if state.substatesAreConcurrent: | |
currentSubstates = state.currentSubstates | |
currentState = None | |
for i in range(len(currentSubstates)): | |
currentState = currentSubstates[i] | |
if currentState._traverseStatesToExit_skipState is True: | |
continue | |
chain = self._createStateChain(currentState) | |
self._traverseStatesToExit(chain.rotate(), chain, state, gotoStateActions) # [PORT] rotate was shift | |
gotoStateActions.append({ action: EXIT_STATE, state: state }) | |
if state.isCurrentState: | |
state._traverseStatesToExit_skipState = True | |
self._traverseStatesToExit(exitStatePath.rotate(), exitStatePath, stopState, gotoStateActions) # [PORT] rotate was shift | |
""" @private | |
Recursively follow states that are to be entered during the state transition process. The | |
enter process is to start from the given state and work its way down a given enter path. When | |
the end of enter path has been reached, then continue entering states based on whether | |
an initial substate is defined, there are concurrent substates or history states are to be | |
followed; when none of those condition are met then the enter process is done. | |
@param state {State} the sate to be entered | |
@param enterStatePath {collection.deque} a deque representing an initial path of states that are to be entered | |
@param pivotState {State} The state pivoting when to go from exiting states to entering states | |
@param useHistory {Boolean} indicates whether to recursively follow history states | |
""" | |
def _traverseStatesToEnter(self, state, enterStatePath, pivotState, useHistory, gotoStateActions): | |
if state is None: | |
return | |
trace = self.allowStatechartTracing | |
# We do not want to enter states in the enter path until the pivot state has been reached. After | |
# the pivot state has been reached, then we can go ahead and actually enter states. | |
if pivotState: | |
if state is not pivotState: | |
self._traverseStatesToEnter(enterStatePath.pop(), enterStatePath, pivotState, useHistory, gotoStateActions) # [PORT] pop, now on deque | |
else: | |
self._traverseStatesToEnter(enterStatePath.pop(), enterStatePath, None, useHistory, gotoStateActions) # [PORT] pop, now on deque | |
# If no more explicit enter path instructions, then default to enter states based on | |
# other criteria | |
elif not enterStatePath or len(enterStatePath) is 0: | |
gotoStateAction = { action: ENTER_STATE, state: state, currentState: False } | |
gotoStateActions.append(gotoStateAction) | |
initialSubstate = state.initialSubstate | |
historyState = state.historyState | |
# State has concurrent substates. Need to enter all of the substates | |
if state.substatesAreConcurrent: | |
self._traverseConcurrentStatesToEnter(state.substates, None, useHistory, gotoStateActions) | |
# State has substates and we are instructed to recursively follow the state's | |
# history state if it has one. | |
elif state.hasSubstates and historyState and useHistory: | |
self._traverseStatesToEnter(historyState, None, None, useHistory, gotoStateActions) | |
# State has an initial substate to enter | |
elif initialSubstate: | |
if issubclass(initialSubstate, HistoryState): | |
if not useHistory: | |
useHistory = initialSubstate.isRecursive | |
initialSubstate = initialSubstate.state | |
self._traverseStatesToEnter(initialSubstate, None, None, useHistory, gotoStateActions) | |
# Looks like we hit the end of the road. Therefore the state has now become | |
# a current state of the statechart. | |
else: | |
gotoStateAction.currentState = True | |
# Still have an explicit enter path to follow, so keep moving through the path. | |
elif len(enterStatePath) > 0: | |
gotoStateActions.append({ action: ENTER_STATE, state: state }) | |
nextState = enterStatePath.pop() # [PORT] pop, now on deque | |
self._traverseStatesToEnter(nextState, enterStatePath, None, useHistory, gotoStateActions) | |
# We hit a state that has concurrent substates. Must go through each of the substates | |
# and enter them | |
if state.substatesAreConcurrent: | |
self._traverseConcurrentStatesToEnter(state.substates, nextState, useHistory, gotoStateActions) | |
""" @override | |
Returns True if the named value translates into an executable function on | |
any of the statechart's current states or the statechart itself. | |
@param event {String} the property name to check | |
@returns {Boolean} | |
""" | |
def respondsTo(self, event): | |
for i in range(len(self.currentStates)): | |
state = currentStates[i] # [PORT] was objectAt i | |
while state is not None: | |
if (state.respondsToEvent(event)): | |
return true | |
state = state.parentState | |
# None of the current states can respond. Now check the statechart itself | |
return hasattr(self[event], '__call__') | |
""" @override | |
Attempts to handle a given event against any of the statechart's current states and the | |
statechart itself. If any current state can handle the event or the statechart itself can | |
handle the event then True is returned, otherwise False is returned. | |
@param event {String} what to perform | |
@param arg1 {Object} Optional | |
@param arg2 {Object} Optional | |
@returns {Boolean} True if handled, False if not handled | |
""" | |
def tryToPerform(self, event, arg1, arg2): | |
if not self.respondsTo(event): | |
return False | |
if hasattr(self[event], '__call__'): | |
result = self[event](arg1, arg2) | |
if result is not False: | |
return True | |
return self.sendEvent(event, arg1, arg2) is True # [PORT] was !! | |
""" | |
Used to invoke a method on current states. If the method can not be executed | |
on a current state, then the state's parent states will be tried in order | |
of closest ancestry. | |
A few notes: | |
1. Calling this is not the same as calling sendEvent or sendAction. | |
Rather, this should be seen as calling normal methods on a state that | |
will *not* call gotoState or gotoHistoryState. | |
2. A state will only ever be invoked once per call. So if there are two | |
or more current states that have the same parent state, then that parent | |
state will only be invoked once if none of the current states are able | |
to invoke the given method. | |
When calling this method, you are able to supply zero ore more arguments | |
that can be pass onto the method called on the states. As an example | |
invokeStateMethod('render', context, firstTime); | |
The above call will invoke the render method on the current states | |
and supply the context and firstTime arguments to the method. | |
Because a statechart can have more than one current state and the method | |
invoked may return a value, the addition of a callback function may be provided | |
in order to handle the returned value for each state. As an example, let's say | |
we want to call a calculate method on the current states where the method | |
will return a value when invoked. We can handle the returned values like so: | |
invokeStateMethod('calculate', value, function(state, result) { | |
# .. handle the result returned from calculate that was invoked | |
# on the given state | |
}) | |
If the method invoked does not return a value and a callback function is | |
supplied, then result value will simply be undefined. In all cases, if | |
a callback function is given, it must be the last value supplied to this | |
method. | |
invokeStateMethod will return a value if only one state was able to have | |
the given method invoked on it, otherwise no value is returned. | |
@param methodName {String} methodName a method name | |
@param args {Object...} Optional. any additional arguments | |
@param func {Function} Optional. a callback function. Must be the last | |
value supplied if provided. | |
@returns a value if the number of current states is one, otherwise undefined | |
is returned. The value is the result of the method that got invoked | |
on a state. | |
""" | |
def invokeStateMethod(self, methodName, args, func): | |
if methodName is 'unknownEvent': | |
self.statechartLogError("can not invoke method unkownEvent") | |
return | |
args = collection.deque(arguments) # [PORT] was .A and shift, now is collection.deque and rotate | |
args.rotate() | |
arg = args[len(args)-1] if len(args) > 0 else None | |
callback = args.pop() if hasattr(arg, '__call__') else None # [PORT] pop, now on deque | |
i = 0 | |
state = None | |
checkedStates = {} | |
method = None | |
result = None | |
calledStates = 0 | |
len = currentStates.get('length'); | |
for i in range(len(self.currentStates)): | |
state = self.currentStates[i] # [PORT] was objectAt i | |
while state is not None: | |
if (checkedStates[state.fullPath]): | |
break | |
checkedStates[state.fullPath] = True | |
method = state[methodName] | |
if hasattr(method, '__call__') and not method.isEventHandler: | |
result = method(state, args) | |
if callback is not None: | |
callback(self, state, result) | |
calledStates += 1 | |
break | |
state = state.parentState | |
return result if calledStates is 1 else None | |
""" @private | |
Iterate over all the given concurrent states and enter them | |
""" | |
def _traverseConcurrentStatesToEnter(self, states, exclude, useHistory, gotoStateActions): | |
for i in range(len(states)): | |
state = states[i] | |
if state is not exclude: | |
self._traverseStatesToEnter(state, None, None, useHistory, gotoStateActions) | |
""" @private | |
Called by gotoState to flush a pending state transition at the front of the | |
pending queue. | |
""" | |
def _flushPendingStateTransition(self): | |
if not self._pendingStateTransitions: | |
self.statechartLogError("Unable to flush pending state transition. _pendingStateTransitions is invalid") | |
return | |
pending = self._pendingStateTransitions.rotate() # [PORT] shift was rotate | |
if not pending: | |
return | |
self.gotoState(pending.state, pending.fromCurrentState, pending.useHistory, pending.context) | |
""" @private | |
Called by sendEvent to flush a pending actions at the front of the pending | |
queue | |
""" | |
def _flushPendingSentEvents(self): | |
pending = self._pendingSentEvents.rotate() # [PORT] shift was rotate | |
if not pending: | |
return None | |
return self.sendEvent(pending.event, pending.arg1, pending.arg2) | |
""" @private """ | |
def _monitorIsActiveDidChange(self): | |
if self.monitorIsActive and self.monitor is None: | |
self.monitor = StatechartMonitor() | |
""" @private | |
Will process the arguments supplied to the gotoState method. | |
TODO: Come back to this and refactor the code. It works, but it | |
could certainly be improved | |
""" | |
def _processGotoStateArgs(self, arguments): | |
processedArgs = { | |
state: None, | |
fromCurrentState: None, | |
useHistory: false, | |
context: None | |
} | |
args = collection.deque(arguments) # [PORT] was .A and shift, now is collection.deque | |
args = (item for item in args if item is not None) | |
if len(args) < 1: | |
return processedArgs | |
processedArgs.state = args[0] | |
if len(args) is 2: | |
value = args[1] | |
if isinstance(value, bool): | |
processedArgs.useHistory = value | |
elif isinstance(value, dict) or isinstance(value, dict): | |
if not isinstance(value, State): | |
processedArgs.context = value | |
else: | |
processedArgs.fromCurrentState = value | |
elif len(args) is 3: | |
value = args[1] | |
if isinstance(value, bool): | |
processedArgs.useHistory = value | |
processedArgs.context = args[2] | |
else: | |
processedArgs.fromCurrentState = value | |
value = args[2] | |
if isinstance(value, bool): | |
processedArgs.useHistory = value | |
else: | |
processedArgs.context = value | |
else: | |
processedArgs.fromCurrentState = args[1] | |
processedArgs.useHistory = args[2] | |
processedArgs.context = args[3] | |
return processedArgs | |
""" @private | |
Will return a newly constructed root state class. The root state will have substates added to | |
it based on properties found on this state that derive from a State class. For the | |
root state to be successfully built, the following much be met: | |
- The rootStateExample property must be defined with a class that derives from State | |
- Either the initialState or statesAreConcurrent property must be set, but not both | |
- There must be one or more states that can be added to the root state | |
""" | |
def _constructRootStateClass(self): | |
#rsExampleKey = 'rootStateExample' | |
#rsExample = self[rsExampleKey] | |
rsExample = self.rootStateExample # [PORT] in kivy will try direct ref | |
initialState = self.initialState | |
statesAreConcurrent = self.statesAreConcurrent | |
stateCount = 0 | |
key, value, valueIsFunc, attrs = {} | |
if hasattr(rsExample, '__call__') and rsExample.statePlugin: | |
rsExample = rsExample(this) | |
if not isinstance(rsExample, State) and rsExample.isClass: | |
self._logStatechartCreationError("Invalid root state example") | |
return None | |
if statesAreConcurrent and initialState is not None: # [PORT] initialState was checked with SC.empty, which checks for null, undefined, and empty string, so ok prolly | |
self._logStatechartCreationError("Can not assign an initial state when states are concurrent") | |
elif statesAreConcurrent: | |
attrs.substatesAreConcurrent = True | |
elif isinstance(initialState, T_STRING): | |
attrs.initialSubstate = initialState | |
else: | |
self._logStatechartCreationError("Must either define initial state or assign states as concurrent") | |
return None | |
for key in self: | |
if key is rsExampleKey: | |
continue | |
value = self[key] | |
valueIsFunc = hasattr(value, '__call__') | |
if valueIsFunc and value.statePlugin: | |
value = value.apply(this) | |
if isinstance(value, State) and value.isClass and self[key] is not self.__init__: | |
attrs[key] = value | |
stateCount += 1 | |
if stateCount is 0: | |
self._logStatechartCreationError("Must define one or more states") | |
return None | |
return rsExample.extend(attrs) | |
""" @private """ | |
def _logStatechartCreationError(self, msg): | |
Logger.debug("Unable to create statechart for {0}: {1}.".format(self, msg)) | |
""" | |
Used to log a statechart trace message | |
""" | |
def statechartLogTrace(self, msg): | |
Logger.info("{0}: {1}".format(self.statechartLogPrefix, msg)) | |
""" | |
Used to log a statechart error message | |
""" | |
def statechartLogError(self, msg): | |
Logger.debug("ERROR {0}: {1}".format(self.statechartLogPrefix, msg)) | |
""" | |
Used to log a statechart warning message | |
""" | |
def statechartLogWarning(self, msg): | |
if self.suppressStatechartWarnings: | |
return | |
Logger.info("WARN {0}: {1}".format(self.statechartLogPrefix, msg)) | |
""" @property """ | |
def _statechartLogPrefix(self): | |
className = _object_className(self.constructor) | |
name = self.name, prefix; | |
if self.name is None: | |
prefix = "{0}<{1}>".format(className, guidFor(self)) | |
else: | |
prefix = "{0}<{1}, {2}>".format(className, name, guidFor(self)) | |
return prefix | |
""" @private @property """ | |
def _allowStatechartTracing(self): | |
return self[self.statechartTraceKey] | |
""" @private """ | |
def _statechartTraceDidChange(self): | |
#self.notifyPropertyChange('allowStatechartTracing') | |
pass # [PORT] notify needed here in kivy? | |
""" | |
@property | |
Returns an object containing current detailed information about | |
the statechart. This is primarily used for diagnostic/debugging | |
purposes. | |
Detailed information includes: | |
- current states | |
- state transtion information | |
- event handling information | |
@returns {Hash} | |
""" | |
def _details(self): | |
details = { 'initialized': self.statechartIsInitialized } | |
if self.name: | |
details['name'] = self['name'] | |
if not self.statechartIsInitialized: | |
return details | |
details['current-states'] = [] | |
for state in self.currentStates: | |
details['current-states'].append(state.fullPath) | |
stateTransition = { active: self.gotoStateActive, suspended: self.gotoStateSuspended } | |
if self._gotoStateActions: | |
stateTransition['transition-sequence'] = [] | |
for action in self.gotoStateActions: | |
actionName = "enter" if action.action is ENTER_STATE else "exit" | |
actionName = "{0} {1}".format(actionName, action.state.fullPath) | |
stateTransition['transition-sequence'].append(actionName) | |
actionName = "enter" if self._currentGotoStateAction.action is ENTER_STATE else "exit" | |
actionName = "{0} {1}".format(actionName, self._currentGotoStateAction.state.fullPath) | |
stateTransition['current-transition'] = actionName | |
details['state-transition'] = stateTransition | |
if self._stateHandleEventInfo: | |
info = self._stateHandleEventInfo | |
details['handling-event'] = { | |
state: info.state.fullPath, | |
event: info.event, | |
handler: info.handler | |
} | |
else: | |
details['handling-event'] = False | |
return details | |
""" | |
Returns a formatted string of detailed information about this statechart. Useful | |
for diagnostic/debugging purposes. | |
@returns {String} | |
@see #details | |
""" | |
def toStringWithDetails(self): | |
str = "" | |
header = self.toString() | |
details = self.details | |
str += header + "\n" | |
str += self._hashToString(details, 2) | |
return str; | |
""" @private """ | |
def _hashToString(self, hashToConvert, indent): | |
hashAsString = '' | |
for key in hashToConvert: | |
value = hashToConvert[key] | |
if isinstance(value, Array): | |
hashAsString += self._arrayToString(key, value, indent) + "\n"; | |
elif isinstance(value, Object): | |
hashAsString += "{0}{1}:\n".format(' ' * indent, key) | |
hashAsString += self._hashToString(value, indent + 2) | |
else: | |
hashAsString += "{0}{1}: {2}\n".format(' ' * indent, key, value) | |
return hashAsString | |
""" @private """ | |
def _arrayToString(self, key, array, indent): | |
if len(array) is 0: | |
return "{0}{1}: []".format(' ' * indent, key) | |
arrayAsString = "{0}{1}: [\n".format(' ' * indent, key) | |
for item, idx in array: | |
arrayAsString += "{0}{1}\n".format(' ' * indent + 2, item) | |
arrayAsString += ' ' * indent + "]" | |
return arrayAsString | |
class StatechartMixin(StatechartManager, StatechartDelegate): # [PORT] also sublassed here was DelegateSupport, from SC | |
pass | |
""" | |
The default name given to a statechart's root state | |
""" | |
ROOT_STATE_NAME = "__ROOT_STATE__" | |
""" | |
Constants used during the state transition process | |
""" | |
EXIT_STATE = 0 | |
ENTER_STATE = 1 | |
""" | |
A Startchart class. | |
""" | |
class Statechart(StatechartManager): | |
def __init__(self): | |
autoInitStatechart = False | |
StatechartManager.__init__(self) |
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